Minimizing astronaut's short and long-term medical risks from exposure to radiation during space missions is a major concern for NASA's manned spaceflight program. For ethical and legal reasons, NASA follows the "as low as reasonably achievable" (ALARA) principal in managing astronaut's radiation exposures. An important aspect of implementing ALARA is the response to space weather events. Of particular concern are solar particle events and, in low Earth orbit (LEO), electron belt enhancements. To properly respond to these events, NASA's Space Radiation Analysis Group (SRAG), in partnership with the NOAA Space Environment Center (SEC), provides continuous flight support during U.S. manned missions. In this partnership, SEC compiles space weather data and makes it available in near real-time to SRAG, and provides appropriate alerts, warnings, and forecasts. SRAG uses this data as input to numerical models to calculate the resulting exposure to astronauts. These calculations form the basis for real-time recommendations to flight control management.

In July 2004, November 2004, and January 2005 there were several energetic SPEs and geomagnetic storms measured onboard the ISS. The ISS instrumentation not only saw the primary effects from these events, but measured subsequent belt enhancements as well. These additional belts could be seen by detectors both outside and inside the vehicle and differed in geographic location (against the natural field drift) from the March 1991 belt enhancement. The measurements of these events and subsequent belt enhancements, along with actual and potential ISS operational issues will be discussed.